TL;DR
Attribution window is the time frame within which a conversion is credited to a marketing touchpoint — e.g., 7-day click + 1-day view (Meta default). Window choice materially changes reported ROAS: shorter windows undercount, longer windows overcount. Best practice: report 1-day, 7-day, and 28-day windows side-by-side and reconcile against blended ROAS.
What is an attribution window?
An attribution window is the period after a click, view, or impression during which a conversion is credited to that touchpoint. Common variants: 1-day click, 7-day click, 28-day click, 1-day view, 7-day click + 1-day view (the Meta default since iOS 14.5). The window is set per ad platform and per campaign; the choice materially changes reported ROAS.
A 7-day click window credits the platform with conversions from any user who clicked an ad within the prior 7 days. A 28-day window credits the platform for clicks up to 28 days back — almost always producing a higher attributed conversion count. The conversion is the same; the credit is different.
Why attribution windows matter
Attribution windows are the single largest source of reported-ROAS variance between platforms. The same campaign that shows 4.2× ROAS on a 7-day-click window will show 6.5× on a 28-day-click and 8.1× when adding view-through. The underlying conversions haven't changed — the credit math has.
For operators, this matters because platform-reported ROAS is structurally optimistic on longer windows. A team comparing Meta 28-day ROAS to Google 7-day ROAS is comparing apples to oranges. Best practice: standardize on one window across platforms for cross-channel decisions, and report multiple windows side-by-side for stakeholders who need both views.
iOS 14.5 (April 2021) reduced Meta's default from 28-day to 7-day click + 1-day view. Brands that didn't recalibrate baselines saw a ~30% drop in reported ROAS that wasn't real — it was the window changing.
Common attribution windows by platform
| Platform | Default | Options |
|---|---|---|
| Meta | 7-day click + 1-day view | 1d, 7d click (+ view options) |
| Google Ads | 30 days | 1d, 7d, 14d, 30d, 60d, 90d |
| TikTok | 7-day click + 1-day view | 1d, 7d, 14d, 28d |
| 30 days | 1d, 7d, 30d, 60d, 90d | |
| Amazon Ads | 7-day click | 1d, 7d, 14d, 30d |
How to choose an attribution window
- Match your purchase cycle. A consumable D2C product (avg 14 days to second consideration) should use 7-day click. A B2B SaaS with 60-day evaluation should use 28-day click + 7-day view.
- Reconcile to total revenue. Sum of all platform-attributed revenue should be 0.7-1.2× of actual revenue. If it's 2×, your windows are too long and you're double-counting; if 0.5×, too short.
- Pick one for cross-channel comparison. 7-day click is the de-facto standard for cross-platform decisions. Use longer windows for individual platform optimization.
- Report multiple windows side-by-side. Best-in-class measurement reports 1-day, 7-day, and 28-day in the same view to make the variance visible.
Related metrics
Attribution window is one input to marketing attribution, first-touch, last-touch, multi-touch attribution, marketing mix modeling, blended ROAS, MER, incrementality, and holdout tests.
At a glance
- Category
- Marketing Metrics
- Related
- 5 terms
Frequently asked questions
What is the default attribution window on Meta?
Since iOS 14.5 (April 2021), Meta's default is 7-day click + 1-day view. The 28-day click window that dominated pre-iOS 14.5 is no longer available without aggregated event measurement workarounds.
Which attribution window should I use?
Match your purchase cycle. Consumable D2C: 7-day click. Considered D2C (apparel, home goods): 7-day click + 1-day view. B2B with 30-90 day cycle: 28-day click + 7-day view. For cross-platform comparison, standardize on 7-day click as the lingua franca.
Does a longer attribution window increase attributed ROAS?
Yes — mechanically and substantially. The same campaign typically reports 50-100% higher attributed conversions on a 28-day window vs. 7-day. The underlying business performance hasn't changed; the credit window has. Always specify the window when reporting ROAS.
What's the difference between view-through and click-through attribution?
Click-through credits the ad for a conversion if the user clicked the ad within the window. View-through credits the ad even if the user only saw it (no click) and converted later. View-through inflates attributed conversions 30-200% and is the source of most cross-platform double-counting. Default to click-only for cross-channel decisions.
Sources
- Meta Business Help. Attribution Settings, 2025. facebook.com
- Google Ads Help. Attribution Models and Windows, 2025. support.google.com
- Northbeam. Multi-Touch Attribution Benchmarks 2025, 2025. northbeam.io
Fairview normalizes attribution windows across platforms to produce a single-source-of-truth blended ROAS — see the operating intelligence overview for the broader category.
Definitions and benchmarks reviewed by Siddharth Gangal, Founder, Fairview.
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